Abstract 2 The Challenges of Defining Defence Needs and Equipment Procurement: Lessons from the UK Approach The definition of the specific capabilities that a state needs for defence purposes is a major challenge, not least because a state's capabilities can cause reactions in others. Analysts of International Relations have long taken note of the 'security dilemma' and its possible consequences in terms of an 'arms race'. However, less attention has been paid to the issue of which particular military capabilities ought to be generated by governments seeking to use defence spending to best effect. Governments in practice must choose among different competing military capabilities, with rational analysis suggesting that effective use of the defence budget would maximise the amount of relevant defence capability being provided. Military capabilities are derived in part from equipment. Equipment choices should be linked to desired military capabilities. This paper will explore how the United Kingdom addresses these issues and seeks to link its equipment equipment choices with the broader tasks of UK defence as well as with contributions anticipated from allies. It will also address the extent to which less developed states could adopt/adapt UK practices in order to improve their defence procurement choices. Professor Trevor Taylor RMCS Cranfield T.Taylor@rmcs.cranfield.ac.uk